PROJECT SUMMARY/ABSTRACT An increasing proportion of prostate cancers of low grade and low potential for progression are diagnosed each year. Most men with these tumors are expected to have comparable survival as other men their age without prostate cancer. Thus, active surveillance, or closely monitoring the course of disease with the expectation to intervene with curative intent given evidence of cancer progression, is universally recommended as a viable management option for men with tumors categorized as ?very low risk? or ?low risk?, particularly given significant morbidities including urinary and bowel incontinence and sexual dysfunction associated with surgery and radiation. Research suggests that men may not be adequately informed about their treatment options and, even more concerning, there is evidence that discussion of the option of active surveillance is done less often for minority men and men of low socioeconomic status. Furthermore, there has been virtually no research on patient-reported outcomes (e.g., physical, mental, psychosocial well-being) and health related quality of life among different racial/ethnic and socioeconomic groups. Conducted within a population-based setting comprising a diverse mix of races/ethnicities and socioeconomic level, the proposed specific aims are to: 1) Examine provider perspectives on patient racial/ethnic perceptions and preferences regarding active surveillance; 2) Examine the prevalence of and determinants of active surveillance among very low and low risk prostate cancer patients by race/ethnicity and socioeconomic status; and 3) Compare changes in patient- reported outcomes by treatment, race/ethnicity, and socioeconomic status, and the contributions of sociodemographic, clinical, and contextual (family, social networks, institutional/provider, neighborhood) factors on patient-reported outcome changes. These aims will be addressed using a mixed methods study integrating qualitative provider and patient interviews, a survey of providers, and a longitudinal patient survey with interviews at baseline (2-3 months after diagnosis) and 12 and 24 months after baseline. All minority patients and a 20% random sample of non-Hispanic Whites will be identified using an early-case ascertainment process from the Greater Bay Area Cancer Registry and the local Veteran's Affairs health system. Multilevel determinants of treatment decision-making process and patient-reported outcomes will include patients' sociodemographic, cultural, psychosocial, and contextual factors. This population-based study, conducted within a diverse population inclusive of a range of medical care settings, will enable us to understand the contributing factors at multiple levels that drive the gaps in receipt of active surveillance. This information is needed to determine who and how best to target interventions to ensure that all men are adequately informed about their treatment options and provided the opportunity to engage in informed decisions regarding their treatments.